Pump for lifting hot liquid



July 9, 1957 R, E, BQGGS 2,798,441 PUMP FOR LIFTING HOT LIQUID 2Sheets--Sheet 1 Filed Oct 1; 1956 1 INVENTOR.

ATTORNEY United States Patent PUMP FOR LIFTING HOT LIQUID Royce E.Boggs, Lakeside, Calif., assignor to Rohr Aircraft Corporation, ChulaVista, Calif., a corporation of California Application October 1, 1956,Serial No. 613,146

6 Claims. (Cl. 103-178) In the manufacture of steel and stainless steelarticles, they are often heat treated by immersing them in hot moltensalt baths for periods of 20 minutes or longer. While they are immersedsmall amounts of scale and slag are formed which get into the salt bathand contaminate it. Upon immersing one batch of articles after another,the amount of scale and slag in the bath progressively increases andcontaminates it to such an extent as to render it inefiicient for itsintended purpose. It has been found that the unwanted oxides or othercompounds formed in the bath are somewhat heavier than the saltcomposing the bath and settle in the bottom of the bath as a sludge. Itis a main purpose of my invention to provide a pump capable of removingthis sludge or a major portion thereof from the bottom of the salt batheven when the bath has a temperature of about 1600 F.

Another object is to provide a pump made entirely of metal which iscapable of withstanding the high tempera ture of the bath repeatedlywithout impairment of its pumping ability.

A further object is to provide a pump composed of a small number ofmoving parts and which is simple in construction and easy to operate.

Another object is to provide means at the bottom of the pump forpermitting the hot salt therein to drain out after the pump has beenused and is being raised out of the salt bath.

Further objects will become apparent as the description of my novel pumpproceeds. For a better understanding of the invention, reference is madeto the accompanying drawings, in which:

Fig. 1 is a view of the pump in operative position in a salt bath alsoshowing some equipment used with the pump, partly in section;

Fig. 2 is a front view, partly in section, showing the outer portion ofthe pump;

Fig. 3 is a bottom view of the pump portion of Fig. 2;

Fig. 4 is a front view of the pump piston rod and piston; and,

Fig. 5 is a sectional view taken on line 5--5 of Fig. 4.

As shown in Fig. 1 the pump is in position for pumping out sludge at thebottom of a salt bath 11 maintained at a temperature of 1600 F. in adeep container or tank 12 by suitable heating means (not shown). Thesalt bath is used for heat treating steel or stainless steel articles(not shown) lowered into the bath and allowed to soak therein. A pair ofdoors 13 having rollers 14 which roll along a pair of channel beams 15may be moved into the position shown to hold the pump upright in bath11. The pump comprises a long cylindrical metal tube 16 to which asurrounding supporting bracket 17 is secured, the bracket 17 resting ondoors 13 to steady the pump. A metal sleeve 18 (see Fig. 2) has a loosesliding fit along the lower end of tube 16, the sleeve having two ormore vertical slots 19 extending therethrough. A collar 20 surrounds andis welded to tube 16, the collar having a plurality of depending fingers21 whose lower ice ends 22 are bent in to enter the slots 1.9. While thetwo slots 19 are shown as being spaced degrees apart for clarity, itwill be understood that they may be spaced degrees apart and also thatmore than two slots may be provided if desired. The fingers 21 thusprevent the sleeve 18 from sliding off tube 16 when the pump is raisedout of bath 11. If desired a reinforcing ring 23 may surround thefingers 21 above their lower ends and be welded thereto.

A check valve 24 is secured to sleeve 18 above the lower end thereof,this valve comprising a metal ring 25 secured in position by four pins26 passing through sleeve 18. A floating disc 27 of a diametersubstantially greater than the inside diameter of ring 25 is adapted torest on the top of ring 25 to close the valve or to move into theposition shown in Fig. 2 to permit liquid to flow up through the valve.Three or more small pins 28 extending through sleeve 18 limit the upwardmovement of disc 27 away from its valve seat. The horizontal bottom face29 of sleeve 18 has a plurality of notches 30 cut therein, these notchesproviding passageways for liquid entering the bottom of the pump whenthe face 29 of sleeve 18 is resting on the floor 31 of tank 12, as shownin Fig. 1. In this pumping position, tube 16 has been lowered from itsposition shown in Fig. 2, the ends 22 of fingers 21 are at the bottom ofslots 19 and the bottom end 32 of tube 16 is at 'a level below thebottom of slots 19 so that when the piston to be described is operated,no fluid can enter the pump through any of the slots 19. In thisposition collar 20 is in contact with the top of sleeve 18, so that theweight of tube 16 is carried by sleeve 18 and the floor 31 of the tank.

The liquid is raised by a piston 33 having a cylindrical hole 34therethrough, the top portion 35 of the piston being cylindrical andhaving sliding contact with the interior face of tube 16. The bottomportion 36 of the piston is frusto-conical in shape to facilitate itsdownward movement through the liquid in tube 16. A floating metal disc37 is adapted to seat on top of piston 33 to block the passage of liquiddownward through hole 34. The piston is attached to the bottom of a longsolid piston rod 38 by three cylindrical bars 39 whose upper ends arewelded to rod 38 and whose lower portions 48 are parallel and are weldedto the top of piston 33. Disc 37 has a loose sliding fit with theportions 40 of bars 39 which keep the disc centered over hole 34 and thebottom end 41 of rod 38 serves as a stop to limit the upward movement ofdisc 37. The top of rod 38 terminates in a ring 42 which has attached acollar 43 whose upper portion is of larger diameter than tube 16 andrests on top of tube 16 to support piston rod 38 and piston 33. Thelower portion 44 of collar 43 is cylindrical and fits in the top of tube16 to center rod 38 therein while the pump is being put in tank 12. Ifdesired, two or more holes 45 may be drilled through collar 43 to permitthe exit of air from tube 16 as the pump is lowered into salt bath 11.All the parts of the pump as above described are preferably made ofstainless steel to minimize oxidation and deterioration at the hightemperatures at which the pump is used.

Attached to and surrounding the top of tube 16 is a metal box 46 whosebottom 47 is at a level below the top of tube 16, the box having adownwardly inclined chute 48 constructed to direct the liquid pumpedinto a can 49.

To operate the pump, a reversible power driven winch 50 is provided, thewinch having a flexible cable 51 to which a hook 52 fitting in ring 42is attached. When the pump is put in position, as shown in Fig. 1, withthe grooves 30 submerged in the sludge at the bottom of salt bath 11,the winch is operated to raise piston rod 38 and piston 33. As thepiston is raised, the liquid above it is forced out of the top of pipe16, falls into box 46 and flows into can 49. As the piston 33 is rising,some of the sludge on the bottom 31 of the tank passes through notches30, and up through the opening in ring 25 causing the disc 27 to riseoff its seat. The sludge continues to rise in pipe 16 as piston 33 risesand with piston having a stroke of 15 feet or more, pipe 16 contains asubstantial volume of sludge when the piston has reached the top of itsstroke. The winch 50 is now reversed and the rod 38 descends under theaction of gravity. As piston 33 descends, disc 37 raises from its seatpermitting the piston and rod 35% to descend through the liquid sludgein pipe 16. The pressure of the sludge in the pipe causes disc 27 tomove down onto its seat and prevent the escape of sludge from the bottomof the pipe. When the piston is at substantially the bottom of tube 16,winch 50 is reversed to raise the piston and on its upstroke the liquidsludge in tube 16 is discharged out of its top and is conveyed into can49. On the upstroke of the piston, more sludge along the bottom of thetank is drawn into notches 3i raises disc 27 and flows up into tube 16.By repeated strokes of the piston the layer of hot sludge which may bean inch or more deep on the bottom of tank 12 may be removed so that itcannot gradually chemically unite with the salt in the bath andcontaminate it.

When the pumping is completed, the piston rod 38 and piston 33 areraised out of tube 16 and tube 16 is raised out of salt bath 11. As thetube is raised, its lower end slides up in sleeve 18 until it is in theposition shown in Fig. 2 whereupon the sleeve and tube rise together.The slots 19 are open and the column of hot salt contained in tube 16drains out through these slots into bath 11. If this salt were allowedto remain in the tube, it would solidify as the tube cooled to normalroom temperature and be difficult to remove later.

This invention may be embodied in other forms or carried out in otherways without departing from the spirit or essential characteristicsthereof. The present embodiment of the invention is therefore to beconsidered as in all respects illustrative and not restrictive, thescope of the invention being indicated by the appended claims, and allchanges which come within the meaning and range of equivalency of theclaims are intended to be embraced therein.

Having thus described my invention, what I claim as new and useful anddesire to secure by Letters Patent is:

1. A pump adapted to lift hot liquid comprising, in combination: a longsubstantially vertical metal tube; a metal sleeve engaging theperipheral wall of said tube and slidable along thelower end thereof;means cooperating with said tube and sleeve to prevent said sleeve fromfalling off the end of said tube; a hollow metal valve seat secured tothe lower end of said sleeve; a metal check valve adapted to rest onsaid valve seat, the lower end of said sleeve being provided with aplurality of openings terminating in its lower end face to admit liquidto said valve seat; a long metal rod extending into and movable in saidtube, the lower end of said rod being provided with a metal pistonslidable along the inner wall of said tube and the top of said rodextending beyond the top of said tube.

2. A pump as claimed in claim 1, in which said metal piston has avertical hole through the center thereof; and a metal plate supportedfor free vertical movement over said piston and adapted upon theupstroke of said piston to rest on the top thereof and prevent thepassage of liquid through said vertical hole.

3. A pump as claimed in claim 2, in which the plurality of spaced apartmetal bars have their upper ends welded to the lower end of said rod andtheir bottom ends welded to the top of said piston, said bars being insliding contact with the periphery of said plate and adapted to preventsidewise movement thereof.

4. A pump adapted to lift hot liquid from a region near the bottom of atank comprising, in combination: a long substantially vertical metaltube, a metal sleeve engaging the peripheral wall of said tube andslidable along the lower end thereof, said sleeve having a plurality ofspaced apart elongated vertical slots extending there through; aplurality of fingers having their upper ends connected to said tube andtheir lower ends extending into said slots, the lower end of said tubeclosing the passageways through said slots in response to the downwardmovement of said tube in said sleeve; a metal ring secured within thelower end of said sleeve; a metal disc disposed on said ring and havinga diameter substantially greater than the inside diameter of said ring,said disc moving up from said ring in response to the movement of liquidupward through said ring; means extending inward from said sleeve abovesaid disc to limit the upward movement of said disc, said sleeve belowsaid ring being provided with a plurality of openings terminating in itslower end face to admit liquid into said sleeve when its lower end faceis resting on the bottom of the tank;

' a long metal piston rod extending into said tube and having its upperend disposed above the top of said tube; and a metal piston attached tothe bottom of said rod and slidable along the inner wall of said tube.

5. A pump as claimed in claim 4, in which the means for limiting theupward movement of said disc consists of a plurality of spaced apartmetal pins extending through said sleeve and disposed in a horizontalplane.

6. A pump adapted to lift hot liquid from the bottom of a tank,comprising: a long substantially vertical metal tube having its topdisposed above the top of the tank; a metal sleeve in engagement withand slidable along the peripheral wall of said tube at the lower endthereof, the upper portion of said sleeve having a plurality of spacedapart slots extending therethrough, the passages through said slotsbeing closed in response to the lowering of said sleeve and tube and theadvancement of the bottom of said sleeve against the bottom of the tank;a metal check valve in the lower end of said sleeve constructed toprevent the passage of liquid downwardly therethrough; a long metalpiston rod disposed in said tube and projecting from the upper endthereof; and a metal piston attached to the lower end of said piston rodand having sliding contact with the inner Wall of said tube.

No references cited.

